Phenol Degradation by UV-Enhanced Catalytic Wet Peroxide Oxidation Process

In this study, degradation of phenol solution by the ultraviolet-enhanced catalytic wet peroxide oxidation process (UV-CWPO) were evaluated via COD removal. Six kinds of homogeneous catalysts (Fe2+, Cu2+, Mn2+, Ni2+, Co2+ and Pb2+) that used frequently in catalytic wet peroxide oxidation were also evaluated. The reactions were carried out in a lab-scale batch photoreactor under rather mild conditions. It was found that the activity of catalysts is in the order: Fe2+ > Cu2+ > Mn2+ > Ni2+ > Co2+ > Pb2+. The effects of different operational parameters such as H2O2 dosage, catalysts dosage, initial pH and initial phenol concentration on the oxidation efficiency of the process were investigated. The results indicated that, when heavy metals in the wastewater itself as catalysts, UV could enhance CWPO oxidation efficiency at normal temperature and pressure. The research has practical significance as the heavy metals in the wastewater itself used as catalysts (no need addition other extra catalyst) to remove the refractory organic pollutants and then easily remove the heavy metals by precipitation. According to the experimental results, a reasonable mechanism was proposed to interpret the oxidation process.